The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Embedded systems have specific real-time requirements that led to the development of dedicated communication protocols. Such systems must face increasing communication needs and the evolution of switched Ethernet architecture. But moving from existing dedicated field-busses architectures to new Ethernet based architectures is not always feasible, due to industrial constraints. In this paper, we compare...
Controller area network (CAN) is nowadays widespread in distributed embedded systems due to its electrical robustness, low price, and deterministic access delay. However, its use in safety-critical applications has been controversial due to dependability limitations. In particular, in a CAN bus there are multiple components such that a single fault of any of them can prevent the communication capabilities...
Today communication networks are more and more used to implement distributed applications concerned by closed loop process controls. These applications require a timeliness service in order to guarantee performances (stability, ...). The goal of this paper is, by considering a closed loop process control application with an open loop transfer function of the type G(s)=K/s(1+taus) (both no position...
This paper presents the TinyCAN, a resource constrained controller area network controller implemented in VHDL language. The core description is fully synthesizable and fits in a FPGA-based platform occupying a maximum of 366 look-up tables. An enhanced error control strategy was elaborated with the aim of producing a more suitable behavior for safety-critical applications. For all that, compatibility...
Embedded systems have specific real-time requirements that led to the development of dedicated communication protocols. Such systems often face increasing communication needs and the integration of switched Ethernet architecture. But moving from existing dedicated field-buses architectures to new Ethernet based architectures is not always easily feasible, due to industrial constraints. In this paper,...
This work pretends to develop a robot for vigilance tasks that are able to tolerate diverse kinds of attacks and be able to operate in environments with elevated electromagnetic noise, being even immune to sabotage provoked by means of high electromagnetic fields. A new CAN based communications system that interconnects the different devices that compose the mobile robot has been developed to achieve...
The use of distributed computing architectures has become commonplace in complex embedded systems with potential advantages, for example, in terms of scalability, dependability and maintainability. One particular area in which that trend can be witnessed is mobile autonomous robotics in which several sensors and actuators are interconnected by means of a control network. In this paper we address one...
At present, a number of platforms are becoming available for the implementation of intelligent field devices, which are based on low-cost microcontrollers and open-source real-time operating systems. To take full benefit from these platforms and to ease the task of developing and porting the application software, a standard interface has to be provided to cope with communication facilities. In this...
A reported liability of the controller area network protocol is that it does not provide a clock synchronization service. Therefore, whenever a CAN-based distributed embedded system requires its nodes to have a common time base, clock synchronization has to be implemented by means of an external mechanism. In a previous work, we proposed a fault-tolerant and high-precision clock synchronization protocol...
This work-in-progress (WIP) paper presents server-CAN and highlights its operation and possible vulnerabilities from a fault tolerance point of view. The paper extends earlier work on server-CAN by investigating the behaviour of server-CAN in faulty conditions. Different types of faults are described, and their impact on sever-CAN is discussed, which is the subject of on-going research
The paper is concerned with the key issue of protecting FlexCAN networks against the babbling-idiot faults, e.g., node faults that busy the bus unduly. A full solution of the problem would enhance the dependability of these networks greatly, making them attractive for safety-critical applications. After analyzing the various modes by which a babbling-idiot fault affects the network operation, a classification...
This paper presents a new method to allow more flexibility on the scheduling of messages across a fieldbus in overload situations. The method proposes the on-line adaptation of the sampling period to the bus load, trying to keep it as low as possible during overloads. The sampling period is allowed to change inside an interval corresponding to 4 to 10 samples per rise time. To assess the solution...
This paper describes the design and implementation of a CAN time-triggered based communication protocol named SCoCAN, (shared channel on CAN), intended for use in distributed control systems, as is the case of autonomous mobile robots. This protocol enables real time communication between different intelligent nodes (sensors, actuators and controllers). The SCoCAN protocol has been implemented in...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.